Starting vegetable seeds indoors

There are some parts of the country where the growing season is so long that you can wait to plant most ordinary vegetables directly outdoors, if you should forget to start them indoors. New Hampshire is not one of those places. The growing season here runs just about 120 days between the average last day of spring frost and the average first day of autumn frost.

For those keeping score at home, that's May 20th to September 20th, just four short months. To be fair, there are some hardy garden plants that aren't really bothered by a little frost every now and then. Spinach, cabbage, brussel sprouts, and a few others can be planted outdoors as soon as the soil can be worked. Of course, if the soil is too cold, then the seeds will remain dormant and risk rotting if the soil is also too wet.

Other vegetables are too delicate to place outdoors until the danger of frost has passed. These include staples of the New England garden like tomatoes, summer squash, cucumbers, and tender herbs like basil. These delicate plants should be started indoors to get a head start on the short growing season.

For most of these, six weeks before the last date of frost is the right time to start them indoors. Varying from that timing depends upon the amount of space you have and your level of gardening ability.

If you have trouble keeping house plants alive, then you're probably going to be better off waiting until about four weeks before the plants can go outside. That gives you less time to screw things up.

On the other hand, if you are very confident in your ability to nurture house plants, then you can go as long as eight weeks indoors, but you may need to transplant them into larger pots once they outgrow the initial seed-starting trays.

In any case, even if the temperatures are warm enough you can't simply take your indoor plants and put them outside in the garden without acclimating them to the conditions to which they'll be exposed there. Just as deadly to seedlings that are used to being indoors is direct sunlight.

If you take tomato plants that you started indoors and place them directly outdoors in a sunny garden, they'll be badly burned and maybe killed completely by the harsh sunlight. They are simply not used to it. You need to give them a chance to gradually toughen up or harden off.

That's done by controlled exposure to the outdoor elements. If you move your seed trays to an unheated three seasons porch they can get used to colder night temperatures. To get them ready for the sun, you can put them outdoors for short periods of time, bringing them in before they are over-exposed. Start with the gentle sunlight of the morning hours and work your way up to full midday sun over time.

Another option is to go ahead and plant them outdoors in the sun, but protect them from the harshest solar rays during the heat of the day. You might cover them with a translucent row cover that knocks some of the strength out of the sun, and keeps them warmer at night until the plants are a little stronger.

So, the point of all this is that I have several varieties of tomatoes, hot peppers and a couple of pickling cucumber bushes already started a couple weeks ago, and the rest of the plants will be starting this week.